scholarly journals Development of a Fruitlet Growth Model to Predict Thinner Response on Apples

HortScience ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 584-587 ◽  
Author(s):  
Duane W. Greene ◽  
Alan N. Lakso ◽  
Terence L. Robinson ◽  
Phillip Schwallier
Keyword(s):  
Growth Rate ◽  
Fruit Set ◽  
Growth Period ◽  
Fruit Growth ◽  
Series Of Experiments ◽  
Individual Trees ◽  
Viable Method ◽  
Final Effect ◽  
June Drop ◽  
Measurement Period

Previous reports have provided evidence that measuring fruit growth rate may be a viable method to predict if a fruit will abscise or persist through the June drop period. A series of experiments were carried out over several years to develop a procedure that could be used to predict the response to a chemical thinner application within 7 to 8 days after application and before thinners exhibit their final effect. The procedure developed involves tagging 105 spurs on seven individual trees distributed appropriately in the orchard. A minimum of two measurements must be made, one 3 to 4 days after application and again 7 to 8 days after application. This model requires that fruit measurement should not start before fruit grow to a diameter of 6 mm and individual fruit within a spur should be numbered and identified. The model is based on the assumption that if fruit growth rate of a particular fruit over the measurement period is less than 50% of the growth rate of the fastest growing fruit on the tree during the same growth period, it will abscise, whereas if fruit growth rate exceeds 50% of the growth rate of the fastest growing fruit, it will persist. All data can be entered into an Excel spreadsheet and the output in the summary page gives the predicted fruit set expressed as percentage of the total number of fruit present. The strategy for crop load adjustment with chemical thinners has evolved over the years to a point where most orchardists plan and are prepared to make two or more thinner applications. The dilemma associated with this approach is to determine if additional thinner applications are necessary. Up to this point a tool designed specifically to provide this information has not been developed.

scholarly journals Development and Testing of a Model to Rapidly Predict Apple Thinner Response

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 793C-793 ◽  
Author(s):  
D.W. Greene* ◽  
A.N. Lakso ◽  
T.L. Robinson
Keyword(s):  
New York ◽  
Growth Rate ◽  
Fruit Set ◽  
Accurate Method ◽  
Fruit Growth ◽  
Cold Weather ◽  
Accurate Predictor ◽  
Accuracy Of Prediction ◽  
June Drop ◽  
Fruit Diameter

Several thinning experiments were initiated in 2003 to test the hypothesis that monitoring fruit growth is an appropriate and accurate method to predict final fruit set early enough to apply supplemental thinners if appropriate. A total of eight thinning treatments were applied in Massachusetts and New York. On the day of thinner application 70 to 100 spurs were tagged on 4-8 trees (replications). All fruit within a spur were individually identified and fruit were measured. At 2 to 3 day intervals fruit diameter was measured at a designated point on the fruit. Growth rate of the fastest growing 20 fruit on the untreated trees was used as the criteria to determine growth rate of fruit that would persist to harvest. A fruit on a treated tree was predicted to abscise if growth rate slowed to 50% or less of the growth rate of the 20 fastest growing fruit on untreated trees. Cold weather in 2003 following thinner application slowed the response time to thinners. Thinning treatments were applied to Delicious, Golden Delicious, McIntosh, and Gala at 7-9-mm stage. BA, carbaryl, and combinations of NAA and carbaryl were used. In Massachusetts accuracy of prediction of final fruit set at 7-11 days after application ranged from 87% to 100% with and average of 95% accuracy compared to final observed drop at the end of June drop in July. In Geneva, N.Y., the temperature was so unseasonably cold following application that prediction of final set at 7 to 11 days after application was between 68% and 79% with an average of 74% accuracy. We conclude that prediction of final fruit set following growth rate of individual fruit shows promise as an accurate predictor of final fruit set early enough to apply supplemental thinners if appropriate.

scholarly journals Influence of M9 Rootstock on the Reproductive Behaviour of Apple Cultivars under Dry, Semi-arid Growing Conditions

2013 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
Hafuz Domi ◽  
Telat Spahiu ◽  
Endrit Kullaj ◽  
Fadil Thomaj
Keyword(s):  
Fruit Set ◽  
Sugar Content ◽  
Global Radiation ◽  
Reproductive Behaviour ◽  
Fruit Growth ◽  
Western Coast ◽  
Growth Dynamic ◽  
Golden Delicious ◽  
Apple Cultivars ◽  
June Drop

In the last decade, apple has been intensively cultivated in the western coast of Albania. The scope of this research was to study the influence of M9 rootstock on the reproductive behaviour of apple cultivars ‘M. Gala’, ‘Golden Delicious’, ‘Starking’, ‘Fuji’ and ‘Pink Lady’. The trial was conducted from 2010 – 2011 in 5-year old orchards with 2,250 trees/ha grown as French axe and in full production located in Lushnja. The following indicators were measured: diameter of two main branches, number of fruits/branch, fruit growth dynamic and sugar content (%). Global radiation, temperature and humidity were recorded. The reproduction behaviour has also been measured by fruiting spurs in the general structure of the canopy as well as the number of fruits formed for each cultivar. The results have shown that in terms of fruit set, cultivars are ranked as follows: ‘M. Gala’ with the highest number of fruits, then ‘Golden Delicious’, ‘Fuji’, ‘Pink Lady’ and ‘Starking’, respectively. The dynamic of fruit dropping shows that ‘Starking’, having the lowest fruit set, after the June drop is more stable while ‘M. Gala’, with the highest fruit set, besides an abundant June drop, had another drop in July.  This is due to higher competition among the fruits and failure of the rootstock to supply the adequate quantities of sap. In terms of fruit growth dynamic, it was observed that intensive growth was measured for all the cultivars during the end of July after which fruit growth slowed down. Changes between cultivars were observed in relation to the maturation period of each cultivar, with ‘M. Gala’ maturing in August, ‘Fuji’ and ‘Pink Lady’ in October and November. ‘Starking and ‘Golden Delicious’ cultivars had a more rapid maturation (20 September), accompanied with a higher sugar content which is far more related to climatic factor rather than M9 rootstock. In conclusion, it was found that the cultivars under study have different reproductive behaviour with M9 rootstock. It can also be stated that ‘Starking’ is not appropriate for this coastal region due to inadequate fruiting behaviour.

scholarly journals Patterns of Sorbitol Metabolism and Availability during Apple Fruit Set

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 887B-887
Author(s):  
Douglas D. Archbold* ◽  
Marta Nosarszewski
Keyword(s):  
Specific Antibody ◽  
Fruit Set ◽  
Sucrose Concentration ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Sorbitol Dehydrogenase ◽  
Prior Work ◽  
Fruit Drop ◽  
June Drop ◽  
Sorbitol Metabolism

Acquiring sufficient carbohydrate is essential for successful apple fruit set. Sorbitol may be the dominant carbohydrate imported by growing fruit, and the rate of sorbitol accumulation may be a function of NAD-dependent sorbitol dehydrogenase (SDH; EC 1.1.1.14) activity. Prior work indicated that SDH activity from whole fruit (seeds plus cortex) increased for 2 or 3 weeks after initiation of fruit growth and then declined through 5 weeks. Using SDH activity assays, an SDH-specific antibody, and SDH-specific probes in Northern analyses, it is evident that SDH is expressed and is active in both apple seed and cortex tissue during the first few weeks of fruit growth. On a per unit protein basis, SDH activity in seeds increased by the pattern described above while that in fruit was generally lower and constant. During this same period of time, the sorbitol content of the expressed sap of apple shoots was analyzed. The sorbitol concentration was 50- to 100-fold higher than the sucrose concentration. The concentrations of both carbohydrates changed in parallel to the change in SDH activity of whole fruit and seeds. The lowest SDH activity and sap sorbitol levels preceded and/or coincided with the beginning of the natural fruit drop (or June drop) period.

scholarly journals Pomegranate Fruit Growth and Skin Characteristics in Hot and Dry Climate

2021 ◽  
Vol 12 ◽  
Author(s):  
Mukul Joshi ◽  
Ze’ev Schmilovitch ◽  
Idit Ginzberg
Keyword(s):  
Growth Rate ◽  
Elastic Modulus ◽  
Growth Parameters ◽  
High Growth ◽  
Growth Period ◽  
Fruit Growth ◽  
Temperate Climate ◽  
Rapid Phase ◽  
Immature Fruit ◽  
Pomegranate Fruit

Pomegranate (Punica granatum L.) fruit is well known for its health-beneficial metabolites. The pomegranate peel consists of an inner thick spongy white tissue, and an outer smooth skin layer that accumulates anthocyanins in red cultivars when ripe. The skin is made up of epidermis cells covered by a cuticle, the latter being the first target of cracking and russeting. The present study focuses on the effect of Israel’s hot and dry climate on pomegranate growth, to elucidate the derived effects on fruit skin characteristics and its putative resistance to the building pressure from fruit expansion. Experiments were conducted for four years, in four orchards located in different regions of the country, each with a different typical microclimate. Fruit-growth parameters were followed using remote-sensing tools, microscopic study, and mineral analysis of the skin, followed by determination of the peel’s elastic modulus. Fruit expanded in two phases: a short rapid phase followed by a gradual phase with a sigmoidal growth-rate pattern. Extreme hot and dry climate during the period of maximal growth rate was associated with restricted growth and a high proportion of small-size fruit. Anatomical study indicated that the skin of mature pomegranate fruit is made up of epidermal cells that are relatively flat and spaced apart, and is expected to be less durable against internal pressure. In contrast, skin of early immature fruit has two layers of dense and rounded epidermis, and is expected to be more resistant to cracking. Tensile strength studies confirmed this trend—skin of mature fruit had a lower elastic modulus than young fruit. However, restrained growth due to extreme environmental cues may result in better resistance of the mature pomegranate fruit to cracking, and in better skin quality and appearance, albeit small fruits. On the other hand, temperate climate at the beginning of the growth period, which allows high growth rate and high daily shrinkage, leads to pomegranate skin disorders.

scholarly journals 684 Thinning and Crop Load Effects on Apple Fruit Growth

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 516E-517
Author(s):  
Duane W. Greene
Keyword(s):  
Growth Rate ◽  
Pollen Germination ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Initial Assessment ◽  
Crop Load ◽  
Specific Chemical ◽  
Load Effects ◽  
Viable Seeds ◽  
June Drop

Chemical thinners can be classified as either blossom thinners or postbloom thinners. Blossom thinners act by inhibit further pollination, pollen germination, or pollen tube growth. At petal fall it is not possible to distinguish between fruit that have been injured by blossom thinners, and those that will persist and continue to grow. The receptacles of blossom thinned fruit do not grow, whereas fruit that has not been treated and that also contain viable seeds, resumes growth within 4 to 6 days, depending upon temperature. Abscission of fruit treated with postbloom thinners does not usually occur until 1.5 to 3 weeks after application. Frequently, it is possible to identify fruit that will abscise and to make an initial assessment of thinning efficacy, within 4 to 6 days following application by measuring fruit growth rate. A reduction in fruit growth by as little as 15% to 20% less than rapidly growing fruit is usually sufficient to assume that the fruit will abscise sometime during the June drop period. The effects of specific chemical thinners on fruit growth and subsequent thinning will be discussed.

scholarly journals Fruit Diameter and Daily Fruit Growth Rate of Three Apple Cultivars on Rootstock–Scion Combinations

HortScience ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Ismail A. Hussein ◽  
Donald C. Slack
Keyword(s):  
Growth Rate ◽  
Growth Period ◽  
Fruit Growth ◽  
Arid Climate ◽  
Cultivar Differences ◽  
Growing Seasons ◽  
Apple Cultivars ◽  
Fruit Diameter

The effect of three vigor-control apple (Malus domestics Borkh.) rootstock (seedling, MM.106, and M.7a) on fruit diameter of three cultivars ('Red Delicious', `Granny Smith', and `Gala') was studied over two growing seasons (1990-91) in the arid climate of Willcox, Ariz. Daily fruit growth rate (DFGR) and effective fruit growth period (EFGP) data indicate cultivar differences in DFGR as well as EFGP. Cultivars with a high DFGR had a relatively shorter EFGP. Rootstock had no significant effect on EFGP. Cultivar x rootstock interaction on fruit diameter was significant for DFGR, but not for EFGP. `Red Delicious' and `Granny Smith' trees produced larger fruits on MM.106 and M.7a than on seedling rootstock. For `Gala', there was no significant effect of all rootstock on fruit diameter.

In-Situ Dual-Wavelength Ellipsometry and Light Scattering Monitoring of Si/Si1−xGex Heterostructures and Multiuantum Wells

1993 ◽  
Vol 324 ◽  
Author(s):  
C. Pickering ◽  
D.A.O. Hope ◽  
W.Y. Leong ◽  
D.J. Robbins ◽  
R. Greef
Keyword(s):  
Growth Rate ◽  
Light Scattering ◽  
Laser Light ◽  
Growth Period ◽  
Laser Light Scattering ◽  
Heterojunction Bipolar Transistor ◽  
Dual Wavelength ◽  
Multi Quantum Well ◽  
Refractive Index Data

AbstractIn-situ dual-wavelength ellipsometry and laser light scattering have been used to monitor growth of Si/Si1−x,Gex heterojunction bipolar transistor and multi-quantum well (MQW) structures. The growth rate of B-doped Si0 8Ge0.2 has been shown to be linear, but that of As-doped Si is non-linear, decreasing with time. Refractive index data have been obtained at the growth temperature for x = 0.15, 0.20, 0.25. Interface regions ∼ 6-20Å thickness have been detected at hetero-interfaces and during interrupted alloy growth. Period-to-period repeatability of MQW structures has been shown to be ±lML.

scholarly journals Effects of KT-30 and GA3 on the Fruit Set and the Fruit Growth of Persimmon cvs. Saijo and Hiratanenashi.

1991 ◽  
Vol 60 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Kojiro Hasegawa ◽  
Norihito Kuge ◽  
Tetsuyuki Mimura ◽  
Yoshikazu Nakajima
Keyword(s):  
Fruit Set ◽  
Fruit Growth

Response of orchard 'Washington Navel' orange, Citrus sinensis (L.) Osbeck, to saline irrigation water. II. Flowering, fruit set and fruit growth

1989 ◽  
Vol 40 (2) ◽  
pp. 371 ◽  
Author(s):  
H Howie ◽  
J Lloyd
Keyword(s):  
Leaf Area ◽  
Citrus Sinensis ◽  
Fruit Set ◽  
High Salinity ◽  
Starch Content ◽  
Fruit Growth ◽  
Leaf Abscission ◽  
Navel Orange ◽  
Washington Navel ◽  
Floral Differentiation

Flowering, fruit set and fruit growth of 'Washington Navel' orange fruit was monitored on 24-year-old Citrus sinensis trees on Sweet orange rootstocks that had been irrigated with either 5 or 20 mol m-3 NaCl for 5 years preceding measurements.Trees irrigated with high salinity water had reduced flowering intensities and lower rates of fruit set. This resulted in final fruit numbers for trees irrigated with 20 mol m-3 being 38% those of trees irrigated with 5 mol m-3 NaCl. Final fruit numbers were quantitatively related to canopy leaf area for both salinity treatments.Despite little difference between trees in terms of leaf area/fruit number ratio, slower rates of fruit growth were initially observed on high salinity trees. This effect was not apparent during the latter stages of fruit development. Consequently, fruit on trees irrigated with 20 mol m-3 NaCl grew to the same size as fruit on trees irrigated with 5 mol m-3 NaCl, but achieved this size at a later date. Measurements of Brix/acid ratios showed that fruit on high salinity trees reached maturity standards 25 days after fruit on low salinity trees.Unimpaired growth of fruit on high salinity trees during summer and autumn occurred, despite appreciable leaf abscission, suggesting that reserve carbohydrate was utilized for growth during this period. Twigs on high salinity trees had much reduced starch content at the time of floral differentiation in winter. Twig starch content and extent of floral differentiation varied in a similar way when examined as a function of leaf abscission. This suggests that reduced flowering and fruit set in salinized citrus trees is due to low levels of reserve starch, most of which has been utilized to support fruit growth in the absence of carbohydrate production during summer and autumn.

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